Yield and Milk Composition at Different Stages of Lactation from a Small Herd of Nguni, Boer, and Non-Descript Goats Raised in an Extensive Production System

Abstract

This study was conducted to evaluate the yield and composition of milk from 30 indigenous South African goats of different genotypes, namely Nguni, Boer, and non-descript, reared under a free-ranging system. Milk yield and composition (milk fat, protein, lactose, solid non-fat, and minerals) from Nguni (10), Boer (10) and non-descript (10) goats were measured and analysed per week at each stage of lactation. Results showed that Nguni goats produced (1.2 ± 0.09, 1.3 ± 0.11 and 1.2 ± 0.07 litres per day) more milk (p < 0.05) at early, mid-, and late stages of lactation than Boer (0.6 ± 0.10, 1.0 ± 0.17, and 0.6 ± 0.09 litres per day) and non-descript (0.3 ± 0.10, 0.3 ± 0.12, and 0.3 ± 0.09 litres per day) goats, respectively. The mean value of milk fat, protein, and lactose content from Nguni goats was 3.98, 3.54, and 5.31; Boer goats, 2.9, 3.59, and 5.04 and non-descript goats, 4.05, 3.39, and 5.02, respectively. There was a significant effect (p < 0.05) of genotypes on milk fat, milk magnesium, and sodium contents of Nguni, Boer, and non-descript goats. It could be concluded that Nguni goats produced more milk than Boer and non-descript goats, but the non-descript goat had a higher mean percentage of milk fat compared to Nguni and Boer goats.